Prognostic Comparison of Acute Exacerbations across Idiopathic Interstitial Pneumonia Subtypes Reveals Inferior Outcomes

Strategic Insights -

Researchers at the Japanese Red Cross Medical Center have conducted a nationwide observational study to evaluate in-hospital mortality differences among major acute exacerbations of idiopathic interstitial pneumonias (AE-IIPs) subtypes. The study, published in Respiratory Investigation, analyzed data from 6,645 patients with AE-IIPs who received high-dose methylprednisolone between July 1, 2010, and March 31, 2023. The researchers found that unadjusted in-hospital mortality rates were 53.9% for idiopathic pulmonary fibrosis (IPF), 40.1% for nonspecific interstitial pneumonia (NSIP), 17.6% for cryptogenic organizing pneumonia (COP), and 49.3% for acute interstitial pneumonia (AIP).

Key Takeaways:

  • The study aimed to evaluate in-hospital mortality differences among major AE-IIP subtypes using a nationwide database in Japan.
  • A total of 6,645 patients were included in the analysis, with IPF, NSIP, COP, and AIP subtypes represented by 2,092, 581, 871, and 3,101 patients, respectively.
  • Unadjusted in-hospital mortality rates were 53.9% for IPF, 40.1% for NSIP, 17.6% for COP, and 49.3% for AIP.
  • After adjustment, in-hospital mortality was significantly higher for IPF (odds ratio [OR], 3.92; 95% confidence interval [95% CI], 3.05-5.04; p < 0.001) and AIP (OR, 2.61; 95% CI, 1.83-3.74; p < 0.001).
  • The findings underscore the inferior prognosis associated with AE-IPF and AIP.

Statistics:

  • 6,645 patients with AE-IIPs were included in the analysis.
  • 53.9% of patients with IPF and 49.3% of patients with AIP had in-hospital mortality.
  • Patients with COP had the lowest in-hospital mortality rate at 17.6%.
  • After adjustment, patients with IPF had a significantly higher odds ratio of in-hospital mortality (3.92; 95% CI, 3.05-5.04).
  • Patients with AIP had a significantly higher odds ratio of in-hospital mortality (2.61; 95% CI, 1.83-3.74).

Sources:

  • Prognostic comparison of acute exacerbations across idiopathic interstitial pneumonia subtypes: A nationwide observational study. Respiratory Investigation, 2025;63(6):1229-1234. (Elsevier - www.elsevier.com; Respiratory Investigation - www.journals.elsevier.com/respiratory-investigation/)
  • NewsRx. New Interstitial Lung Disease Study Findings Have Been Reported by Researchers at Japanese Red Cross Medical Center (Prognostic comparison of acute exacerbations across idiopathic interstitial pneumonia subtypes: A nationwide observational study). Respiratory Therapeutics Week. October 20, 2025; p 3241.